The purpose of this research study was to determine if there was an academic achievement gap between third through eighth-grade students in Title I and Non-Title I schools in the academic content areas of English Language Arts and Mathematics. The study focused on the following subgroup: economically disadvantaged students. The data was gathered from an analysis of a standardized test in English Language Arts and Mathematics of third through eighth-grade students. Within the suburban southwest school district that was being studied, the district formation of schools varied: fifteen schools in the district service kindergarten through fifth-grade students, four schools in the district service kindergarten through eighth-grade students, and five schools in the district service sixth through eighth-grade students. The data was collected from the 2017 Arizona's Measurement of Educational Readiness to Inform Teaching (AzMerit) scores. The Arizona's Measurement of Educational Readiness to Inform Teaching (AzMerit) assessment is a yearly standardized assessment test, starting in the third-grade, used to evaluate student academic progress in the state of Arizona. In summary, in grades third through fifth, there was a significant difference between students in both English Language Arts and Mathematics scores between Title I and Non-Title I schools. Also, in grades third through fifth, there was a significant difference between socioeconomically disadvantaged students in both English Language Arts and Mathematics scores between Title I and Non-Title I schools. When it came to the middle school grades, the data results changed. In grades sixth through eighth, there was no significant difference between students in both English Language Arts and Mathematics scores between Title I and Non-Title I schools. But, when looking at socioeconomically disadvantaged students in grades sixth through eighth the data showed there was a significant student achievement gap difference between sixth and eighth-grade students English Language Arts (ELA) scores between Title I schools and Non-Title I schools. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]